Jan 14, 2012

Blues Dancing + Engineering =

One of my classes last semester was called Modeling and Simulation of the Physical World. I've never figured out a nice way to describe that class in terms that don't include the class's name, but the very basic gist is that you use a computer to predict or otherwise analyze a real-world system. For my final project in this class, I was paired up with a friend of mine named Ndungu (pronounced dung-uh). Both of us being dancers, we decided to model a dip in blues dancing.

The absolute minimal amount of background knowledge needed to understand this is that a blues dance consists of two dancers, the lead and the follow. The lead is typically the man, and the follow is typically the woman, although that's not always the case. A dip is one of those fancy things you see on TV, where the follow generally bends backward, held up by the lead.
Like so.
Thank you to the folks at this blog I've never heard of,
as well as public domain laws.
Ndungu and I planned use our model to figure out how far and how fast a lead can dip his follow without dropping her, lest our dancers arrive at some rather... catastrophic results.

In order to get our feet on the ground, so to speak, we needed to be able to draw our physical system on paper. That way we could do all sorts of fancy trigonometry and physics in order to make our model. After a fair amount of simplification, we managed to create the following, totally accurate diagram:

The lead is on the left, the follow on the right.
The things in between them are arms.

A few interesting things about our model:
  • The lead's front leg would grow and shrink over time, depending on how he bent his knee
  • The lead's torso and back leg would always create a straight line
  • The follow's shins would always be perpendicular to the ground
  • The follow's torso and thighs would always create a straight line
Like I said. Totally. Accurate.

Next, we needed to take a few measurements that we would be able to plug into the program we would soon make. We collected values including Ndungu's height, the height of his shoulder, the height of his pelvis, the distance between his feet when he dips, the angle of his torso from the horizontal, and so forth.

Unfortunately, we didn't always have all the measuring equipment we wanted at all times. For example, a protractor was sometimes hard to find; but remember, we're trained professionals in training. So obviously, the natural solution was to find a picture of a protractor online, and just hold my laptop up to Ndungu's or his partner's leg. Many of our measurements were along the lines of "68... ish? I'll call it 68."

Slightly more difficult than the problem of recording an angle was that of recording weight. Ndungu and I already felt uncomfortable asking a woman to please stand on a scale for us, due to the fact that that would involve asking a woman her weight, generally considered a no-no. Once we managed to surmount that issue, though, we realized that in order to record the normal force exerted by one's leg, we would need to dance on top of the scale. This was particularly exciting when we were recording the maximum normal force that one's leg could hold before dropping the follow; this meant that we had to lay down cushions through the hallway right next to the scale, and Ndungu had to stand in just the right position with one foot on the scale while he dropped our generous dance partner time and time again, as I scrambled to record their angle with my laptop-protractor.

But these recording inaccuracies pale in comparison to the glory that was our tension force. In order to determine the force that the lead's hand exerts on the follow's back, we needed to basically put the scale on our follow's back and dance like so. Unfortunately, the scale wouldn't quite stay in place. So we resorted to iffier methods.

We needed two data points. So, data point number 1: exerting 5 pounds of force on the follow. Ndungu danced with our follow, and dipped her back until he felt like he was sort of exerting about 5 pound of force. I asked how he could possibly know that he was exerting 5 pounds of force; obviously, he had picked up a 5-pound weight the previous morning, and was just sort of gauging what felt similar. When Ndungu was at 5 pounds of tension force, I recorded the angle.

Data point number 2: threshhold. This time, Ndungu danced with our follow until he reached his threshhold, at which point she of course fell onto the cushions that we had supplied her with. Then, Ndungu quickly ran over to a doorway in the hall, and positioned the scale on the back of the door at about shoulder-height. He then struck a dancing position with the door, and exerted what felt like the same force on his new "partner." That way we were able to find his threshhold tension force.

Suffice to say, we had a difficult time creating our actual model on the computer. A bunch of arm-waving went into many of our graphs ("Well, the normal force on the front leg sorta feels like this kind of graph... let's call it that"), which we later simplified down. At one point, I tested our model for a theoretical one-minute dip: obviously longer than any realistic dip would take, but if our model worked then there shouldn't have been a problem. Unfortunately, according to our model, over the course of one minute, our highly impressive lead managed to perform a 3,500,000-degree dip. That's right, 3.5 megadegrees, a unit which I never hope to use again.

After fixing up our model a little more, we were faced with the difficult problem of finding the equation of a parabola. We had the vertex and two other points on the parabola. This was the kind of math that we had been doing since seventh grade, and here were at one of the top engineering schools in the country, unable to perform this sort of witchcraft. We asked anyone who happened to walk through the room for help, and it took us at least five or six lifelines until we finally found someone with the mathematical sagacity to help us. There is no explaining how much difficulty we had with this problem.

Finally, we had a working model which produced reasonable results. Ndungu and I had realized somewhere along the line that we could just plug in different values for the lead's height, weight, and normal threshhold, and would thus be able to compare two different leads and their maximum dip time and angle. The only thing to do after making that kind of realization was to compare the two of us, and figure out whom, mathematically, was the superior dancer.

Upon further thought, we realized that we could feasibly put this on our presentation poster. It was sort of like doing useful work with our model, after all. Sorta ish. The prize for the victor: that the loser would have to be the one to announce the winner during presentation, essentially admitting his inferiority in front of our professors.

We devoted a quarter of our poster to our competition, under the heading "GREG VS. NDUNGU: Who's the better dancer?", with a nice little graphic to showcase our competition:

Let's just say it's not important who won anyway; it's all in the sport of the thing anyway, and really, it was more about the learning than it was about the competition, so what does it matter who won? But that having been said, I did a fair amount of announcing the victor the day of our presentations.

Thus ended the least scientifically accurate study ever conducted by would-be engineers.

Jan 9, 2012

From the Annals of Greg Edelston, Ages Five Through Eight

I recently discovered my old diary. I received it in 1998, when I was five years old. I'll let it speak for itself. I have reproduced all the text to the best of my ability. Bracketed text was added in by Present-Day Me. I don't think I knew what brackets were.


I hAVe cool
    It is BASeBALL

[They were really cool, in my defense.]


Still 1998.

[I suspect that I lost interest here.]


Still 1998.
hope you'r hAppy now.
happy neW-

[Two things to explain: one, I believe the "love, Greg" was meant to harken to the "dear Diary" standard; and two, it is of my opinion that I had just learned about using a dash to indicate that you would be continuing your word on the next line.]


1999 JAN1'St
i WiLL try 6 New FOOD's WhiNe
Wke Whi WheN
im 6.
iL EeAt
AND Meet
    NeW FreND'S.


Mar, 30, 99
Oh. eveonye
thinks that Captin -
Baca stinks
like a yellow
peice of cheese.
But Me I say
He's OK ais long
a BEAR ! [This exclamation point has a sad face instead of the dot.]

[First piece of important background information: Captain Baka was one of my invisible friends. But that's a story for a different day.]
Second: This was based on a song sung by D.W. on the TV show Arthur. The original lyrics can be found on this imdb page, as well as in the proceeding diary entry. I apparently channeled my artistic musings through this song.]


      Oh, ever-
       YBodY thin-
         ks that my
          Brother stin-
             ks like a
peise of Chees.,
   But Me i say
he's O.k. as-
  long as ther's
    a Breeze!



  Oh, evryBoby
   that I stink
-nk like
  a Brown Ch-
   [illegible symbol]! But me
  I say i'm o.k
   as lonG as

[I must have really liked this song.]


Dear DiAry,
 SleeP Well.
  SleeP Good.
Be nice ToM-
 Good BoY.

[My best guess is that this was a further extrapolation from the whole "Dear Diary"/writing-to-the-diary-and-therefore-it-must-be-a-sentient-creature thing? But I don't have any recollection of thinking that my diary was alive.]



[Brevity is wit.]


Dear Diary,
I'm 7 now
and it's 8/14/00.
BOTH "sissies"
am annoy me.

Write back
   P.S. I have been
taking piano les-
sons 3| giving

[Okay. First off, obvious time lapse here. Next. I would like to formally apologize to Rosie and Julie. You do not annoy me. And I'm sorry for calling you sissies. Next: I do not know how I expected my diary to write back soon, lest if Tom Riddle resided therein. And finally, I should note that that symbol at the end was supposed to be an ampersand.]


Dear Diary,
I have a
connfetion to make,
O.K.? Good. Now,
here it is. I
sleep with two
blankies. Piano
lessons go well!
Your pal,


[I don't remember ever going by Gregory. I do remember being terribly ashamed about Bankie and Binky. Bankie was the original. When he started to get too tattered, I received another blankey. I think my parents expected I would stop using the first one. As if. As it happened, a third one followed suit thereafter: Bankie Jr., or B.J., for short. Ain't no hatin' on my blankies.]



Dear Diary,

I started writing

a somg! For school

I've been put in

3N. Miss Nelson's

O.K. Today, we earned

[This song was AWESOME. It was all about different kinds of food. If I remember correctly, it was heavily influenced by *NYSNC. The only lyrics I can remember are the two lines, "You can have yogurt with sprinkles / Just don't get caught making a tinkle" (referring, of course, to peeing; I think it was the only rhyme for "sprinkle" I could think of).
Also, 8-Year-Old-Me doesn't know jack about good teachers. Miss Nelson was the coolest.]

Jan 2, 2012


Several weeks ago, I started working out in preparation for the Tough Mudder event in May. I figured, while I was at it, I may as well go whole-hog and get actually healthy. I had never in my life particularly cared about what went into my body, and certainly never thought about the long-term consequences of my nutritious habits. So if I was going to get fit, I may as well actually get fit.

The obvious first step to my healthifying: I needed to put on some weight. At this time, I weighed 129 pounds. 130 is the bottom of the healthy body weight range for my height. I had been grossly underweight for as long as I could remember. (However, it should be noted that I was born at 10 pounds, 4 ounces, which is kind of disgustingly huge; thus, the mean value theorem dictates that at some point in time, I was a healthy body weight.) If I put on some muscle weight, great; but I needed some fat-pounds, too, because I was sorely lacking.

In my internet-research-studies, I discovered a program called GOMAD, or Gallon of Milk a Day. Under GOMAD, shockingly enough, you drink a gallon of milk a day. This is apparently a pretty good program recommended for some underweight people who are starting training. The weight that you put on from GOMAD is also sustainable, because it "teaches" you how to eat more, allowing you to keep your weight after you've stopped the program. I wasn't 100% done researching the topic, but I figured I would get a head-start, and if it turned out that it wasn't for me, then I surely wouldn't die from what I'd had by then.

I found out about this program at about 2:00 in the afternoon. I had already missed two meals' worth of opportunities to drink milk. So I had to hustle. I made a beeline for my campus's dining hall, and got to work.

Next problem. I find milk rather unappealing. I just don't enjoy drinking milk. I eat my cereal dry. Fortunately, my school's dining hall also happened to have an endless supply of chocolate syrup. So my GOMAD was more accurately going to be GOCMAD: Gallon of Chocolate Milk a Day.

After some inquiry of the dining hall staff, I learned that one of our paper cups could hold 12 fluid ounces. After some subsequent inquiry of Wolfram Alpha, I learned that one gallon was equal to 128 fluid ounces. So I was going to need roughly 11 cups of chocolate milk throughout the day. No matter how I sliced that, that was HUGE.

Imagine this.
Now imagine eleven of it.
Now imagine that every day.
In my first sitting, I got through three cups, and was feeling full to bursting, not to mention a little grossed out. I figured I'd come back later for the rest of today's gallon.

Dinner was my second sitting. I got through two more cups, bringing me to almost halfway through for the day. I was ready to call it a day. I wish there were more to the story of my actual drinking, but that's about it - I drank 60 fluid ounces of chocolate milk that day, and it was really gross, and so I stopped.

Back to the wonderful world of Wolfram Alpha, I checked out the nutrition facts for the chocolate milk I had drunk that day. (This was, mind you, in addition to my three meals.) That day, in chocolate milk alone, I had consumed 1440 calories (which, mind you, is as much as some people will eat in an entire day); I had had  122% the recommended daily value of saturated fat; 119% the RDV of protein; 225% the RDV of calcium; 229% the RDV of Vitamin D105% the RDV of Vitamin B12; 183% the RDV of phosphorous; and 304% the RDV of riboflavin, whatever that is. And those are just the ones over 100% - almost everything else was above 50% at least. All in all, I had consumed over 4 pound of chocolate milk that day, which was over 3% of my body weight. I weighed myself again - I was now over 132 pounds, a whopping 3 pounds more than I had weighed not even a day ago.

And I had planned on doing double this. Every day.